The present invention relates generally to agricultural machinery and, more particularly, to a controllable pivoting device to allow a frontal attachment on an agricultural machine to be pivoted relative to the feed rake or machine housing of the agricultural machine.
Agricultural harvesting machines are often equipped with a so-called leveling mechanism for ensuring that the devices in the machine housing remain generally upright so as to retain their functionality even when the agricultural machine is operating on a slope. Various leveling systems are known. One system involves a drive axle which is rigidly connected to the machine housing and which is provided with drive wheels that are pivotally mounted at its ends through the intermediary of gear trains (DBP 4 131 433). The height of each drive wheel is thus independently adjustable whereby the machine housing always adopts an upright position when working on a slope. The adjustment of the set of wheels is effected automatically when harvesting on a slope. To this end, the machine housing is equipped with at least one pendulum switch or an inclination sensor. After they have been appropriately converted, the signals from the at least one pendulum switch or the inclination sensor are used for controlling the wheel adjustment. U.S. Pat. No. 2,904,341 discloses an axle constructed in the form of a pendulum axle, which is supported such that it is hydraulically adjustable relative to the machine housing for the same purpose.
If the drive wheels are adjusted when working on a slope, it inevitably follows that the machine housing and the housing of the feed rake that is connected thereto in a torsionally stiff manner will be held upright. In contrast thereto however, the frontal attachment of the machine, which may have a cutter bar or other implement, should be guided such that it is maintained as uniformly parallel to the ground as possible so as to achieve optimal harvesting of the crop. Accordingly, it is necessary for the frontal attachment to be pivotal relative to the machine housing or the housing of the feed rake so that the frontal attachment will remain parallel or virtually parallel to the terrain. Since the terrain is constantly altering during the harvesting process, an automatic means for regulating or adjusting the frontal attachment is desired so as to lighten the load on the driver. The machine housing or the feed rake has a rectangular opening at the inlet end thereof. When working on flat land, this opening practically coincides with the feed opening in the wall portion of the frontal attachment. However, when working on a slope, the two openings are mutually displaced so that the width of the opening available for the passage of the crop may become severely restricted especially at the side boundaries thereof. Accordingly, the angle to which the frontal attachment can be adjusted is limited as a blockage of the harvested crop prior to the feed rake must be avoided at all costs. Consequently, as from a certain angle of inclination, the frontal attachment will no longer be parallel or virtually parallel to the slope, making it difficult to guide the cutter bar under the stalks when harvesting flattened grain.
The present invention is directed to overcoming one or more of the problems set forth above.
An aspect of the invention is to maximize the available pivotal adjustment of a frontal attachment of an agricultural machine relative to the housing of the machine, while minimizing any blockage of the crop feeding path from the frontal attachment to the housing.
In accordance with the above aspect of the invention, there is provided a controllable pivoting device that includes a pivot element or frame which is connected to a machine housing or feed rake of an agricultural machine such that it is pivotal about a horizontal axis. The frontal attachment is attached to the pivot frame in a rotatable or pivotal manner, which allows it to independently rotate about a horizontal axis.
The pivotal movement of the frontal attachment relative to the machine housing or the feed rake is thus effected in two approximately vertical, mutually separated pivot planes, whereby the pivot frame is disposed between the two pivot planes. The maximum possible angle of adjustment of the frontal attachment is made up of the adjustments that can be made in the two pivot planes. Due to this division of the possible pivotal movement between the two pivot planes, any blockage of the crop feeding path from the frontal attachment to the feed rake is minimized.
This aspect of the invention is merely illustrative of the innumerable aspects associated with the present invention and should not be construed as limiting in any manner.
The above and other aspects, features and advantages of the present invention will become apparent from the following detailed description when taken in conjunction with the accompanying drawings.